hpt366: fix section mismatch warnings

Fix following warnings:
WARNING: o-sparc64/vmlinux.o(.data+0x195a38): Section mismatch in reference from the variable hpt37x_info.0 to the variable .devinit.data:hpt370
WARNING: o-sparc64/vmlinux.o(.data+0x195a40): Section mismatch in reference from the variable hpt37x_info.0 to the variable .devinit.data:hpt370a
WARNING: o-sparc64/vmlinux.o(.data+0x195a48): Section mismatch in reference from the variable hpt37x_info.0 to the variable .devinit.data:hpt372
WARNING: o-sparc64/vmlinux.o(.data+0x195a50): Section mismatch in reference from the variable hpt37x_info.0 to the variable .devinit.data:hpt372n

Replace a static array with a small switch resulting in
more readable code.
Mark the pci table __devinitconst.

A lot of variables are const but annotated __devinitdata.
Annotating them __devinitconst would cause a section type
conflict error when build for 64 bit powerpc.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>